This guide walks you through how to reset the engine light on a 2018 Harley-Davidson Road Glide using simple methods and professional tools. Whether you’ve fixed the issue or just want to clear the code, we’ll help you do it right—without risking damage to your bike.
Key Takeaways
- Understand why the engine light came on: The check engine light can signal anything from a loose gas cap to a serious engine problem. Always diagnose the root cause before resetting.
- Use the right tools: A basic OBD2 scanner is the safest and most effective way to reset the engine light on a 2018 Road Glide. Avoid unplugging the battery unless necessary.
- Follow proper reset steps: Connect the scanner, read the trouble codes, clear them, and verify the light stays off after a test ride.
- Don’t ignore recurring lights: If the engine light returns after resetting, there’s likely an ongoing issue that needs professional attention.
- Maintain your bike regularly: Prevent future engine lights by keeping up with oil changes, air filter replacements, and fuel system care.
- Know when to see a mechanic: Some problems, like sensor failures or ignition issues, require expert diagnosis and repair.
- Keep records: Document any codes and repairs for future reference or resale value.
How to Reset Engine Light on 2018 Road Glide
If you’re riding a 2018 Harley-Davidson Road Glide and the dreaded check engine light pops up, don’t panic. While it can be alarming, the engine light—also known as the malfunction indicator lamp (MIL)—is simply your bike’s way of saying, “Hey, something needs attention.” The good news? In many cases, you can reset it yourself without a trip to the dealership.
This comprehensive guide will walk you through how to reset the engine light on a 2018 Road Glide safely and effectively. We’ll cover why the light comes on, the tools you’ll need, step-by-step reset methods, and what to do if the light keeps coming back. Whether you’re a seasoned rider or new to motorcycle maintenance, this guide is designed to be easy to follow, practical, and packed with real-world tips.
By the end of this article, you’ll know exactly how to clear that engine light—and more importantly, how to make sure it doesn’t return.
Why Does the Engine Light Come On?
Before you reset the engine light, it’s important to understand what might have triggered it in the first place. The 2018 Road Glide uses an onboard diagnostic system (OBD2) that monitors various sensors and systems in the engine, fuel system, exhaust, and emissions. When something goes outside normal operating parameters, the system stores a trouble code and illuminates the check engine light.
Common reasons for the engine light to come on include:
- Loose or faulty gas cap: A loose cap can cause a vacuum leak in the fuel system, triggering a code like P0455 (evaporative emission control system leak).
- Oxygen sensor issues: The O2 sensors monitor exhaust gases. If they fail or get dirty, they can send incorrect data, leading to poor fuel economy and emissions problems.
- Spark plug or ignition coil problems: Misfires can trigger codes like P0301–P0308, indicating a cylinder isn’t firing properly.
- Mass airflow (MAF) sensor contamination: Dirt or oil on the MAF sensor can cause incorrect air-fuel mixture readings.
- Exhaust gas recirculation (EGR) valve malfunction: A stuck or dirty EGR valve can trigger emissions-related codes.
- Fuel injector issues: Clogged or leaking injectors can affect engine performance and trigger warning lights.
- Battery or charging system problems: Low voltage or poor connections can confuse the ECU and cause false codes.
The key takeaway? Don’t just reset the light—fix the problem first. Resetting without addressing the root cause is like turning off a smoke alarm while your kitchen is on fire. It might look fixed, but the danger remains.
Tools You’ll Need to Reset the Engine Light
To reset the engine light on your 2018 Road Glide, you’ll need a few basic tools. The most important is an OBD2 scanner. Here’s what to look for:
OBD2 Scanner
A good OBD2 scanner is essential. For Harley-Davidson motorcycles, especially the 2018 Road Glide, you’ll want one that’s compatible with Harley’s proprietary diagnostic system. While generic OBD2 scanners can read basic codes, they may not access all Harley-specific data.
Visual guide about How to Reset Engine Light on 2018 Road Glide
Image source: cdn.dealeraccelerate.com
Recommended options include:
- Harley-Davidson Digital TechScan: The official tool used by dealers. It’s expensive but offers full diagnostics and tuning capabilities.
- Foxwell NT510 or NT520: Aftermarket scanners that support Harley-Davidson models and can read and clear codes, view live data, and even reset service reminders.
- BlueDriver or OBDLink MX+: Bluetooth-enabled scanners that work with smartphone apps. Great for casual use and basic diagnostics.
Basic Hand Tools
You may also need a few basic tools depending on the issue:
- Screwdrivers (Phillips and flathead)
- Socket wrench set (for accessing the battery or sensors)
- Cleaning supplies (for sensors or the gas cap)
- Electrical contact cleaner (for cleaning connectors)
Smartphone or Tablet (Optional)
If you’re using a Bluetooth scanner, you’ll need a compatible device with the scanner’s app installed. Most apps are free and available on iOS and Android.
Step-by-Step Guide to Reset the Engine Light
Now that you understand the cause and have the right tools, let’s walk through the process of resetting the engine light on your 2018 Road Glide.
Step 1: Diagnose the Problem
Before resetting, connect your OBD2 scanner to read the trouble codes. This will tell you exactly what’s wrong.
- Locate the OBD2 port on your Road Glide. It’s usually under the left-side cover, near the fuse box. You may need to remove the cover with a screwdriver.
- Plug in your OBD2 scanner. Turn the ignition to the “ON” position (do not start the engine).
- Follow the scanner’s instructions to read the codes. Most scanners will display a list of active or stored trouble codes (e.g., P0134, P0302).
- Write down the codes and look them up using the scanner’s built-in database or an online Harley code reference.
Example: If you see code P0134, it means the oxygen sensor in bank 1, sensor 1 is not responding. This could be due to a faulty sensor, wiring issue, or exhaust leak.
Step 2: Fix the Underlying Issue
Once you know the problem, take steps to fix it. Here are a few common fixes:
- Loose gas cap: Tighten it until it clicks 3–5 times. If the cap is cracked or worn, replace it.
- Dirty MAF sensor: Use MAF cleaner (not regular spray) to gently clean the sensor element. Let it dry completely before reassembling.
- Faulty O2 sensor: If the sensor is old or damaged, replace it. This may require removing the exhaust header.
- Spark plug issues: Remove and inspect the plugs. Replace if worn, fouled, or damaged.
Tip: Always disconnect the battery before working on electrical components to avoid short circuits.
Step 3: Clear the Trouble Codes
After fixing the issue, it’s time to reset the engine light.
- Reconnect your OBD2 scanner.
- Turn the ignition to “ON.”
- Navigate to the “Clear Codes” or “Erase DTCs” option on your scanner.
- Confirm the action. The scanner will send a command to the ECU to delete the stored codes.
- The check engine light should turn off immediately or after a few seconds.
Note: Some scanners may require you to turn the ignition off and back on after clearing codes.
Step 4: Test Ride and Verify
Don’t assume the job is done just because the light is off. Take your Road Glide for a short test ride (10–15 minutes) to ensure the problem is truly resolved.
- Drive at various speeds and loads (city, highway, hills).
- Monitor the dashboard for any warning lights.
- If the engine light stays off, you’re good to go.
- If it comes back on, the issue wasn’t fully fixed—or there’s another problem.
Step 5: Monitor for Recurrence
Even if the light stays off, keep an eye on your bike’s performance. Watch for:
- Rough idling
- Reduced fuel economy
- Hesitation or stalling
- Unusual noises
If any of these occur, recheck the codes. The problem may be intermittent or require deeper diagnosis.
Alternative Methods to Reset the Engine Light
While using an OBD2 scanner is the recommended method, some riders try other approaches. Here’s what you need to know about alternatives.
Method 1: Disconnect the Battery
Some people believe that disconnecting the battery will reset the engine light. While this can work in rare cases, it’s not reliable and can cause other issues.
How to do it:
- Turn off the ignition and remove the key.
- Disconnect the negative (-) battery terminal using a wrench.
- Wait 10–15 minutes to allow the ECU to fully reset.
- Reconnect the battery and turn the ignition on.
Why it’s not recommended:
- It may not clear all codes, especially on modern bikes with persistent memory.
- It can reset other systems like radio presets, clock, and trip meters.
- It doesn’t fix the underlying problem—just hides the symptom.
Only use this method if you don’t have a scanner and need a temporary fix. But don’t rely on it long-term.
Method 2: Ride It Out (Not Recommended)
Some riders hope the light will go away on its own after a few hundred miles. While the ECU may eventually clear minor, intermittent codes, this is risky.
- Serious problems won’t fix themselves.
- You could cause further damage by ignoring the issue.
- Emissions-related codes may prevent your bike from passing inspections.
Bottom line: Don’t wait. Diagnose and fix the problem.
Troubleshooting Common Issues
Even with the right tools and steps, you might run into problems. Here’s how to handle common issues.
The Light Won’t Turn Off After Reset
If the engine light comes back on immediately or after a short ride, the issue wasn’t fully resolved.
- Recheck the trouble codes. The same code may reappear.
- Inspect wiring and connectors for corrosion or damage.
- Ensure all repairs were done correctly (e.g., sensor properly seated, gas cap tight).
- Consider a professional diagnostic if the problem persists.
Scanner Won’t Connect
If your OBD2 scanner won’t communicate with the bike:
- Check that the ignition is on.
- Ensure the OBD2 port is clean and undamaged.
- Try a different scanner or cable.
- Verify the scanner is compatible with Harley-Davidson motorcycles.
Multiple Codes Appear
If several codes show up, prioritize them. Some codes are “downstream” effects of a primary issue. For example, a misfire (P0300) can trigger an O2 sensor code (P0134).
- Address the most critical code first (usually related to engine performance or emissions).
- Fix one problem at a time and recheck codes.
Preventing Future Engine Light Issues
The best way to avoid resetting the engine light is to prevent it from coming on in the first place. Here are some maintenance tips for your 2018 Road Glide:
- Use quality fuel: Stick to top-tier gasoline with the correct octane rating (usually 91 or higher for Road Glides).
- Replace the air filter regularly: A clogged filter restricts airflow and can trigger MAF-related codes.
- Change spark plugs on schedule: Harley recommends replacing plugs every 10,000–15,000 miles, depending on riding conditions.
- Inspect and clean sensors: Periodically check the MAF and O2 sensors for dirt or damage.
- Tighten the gas cap after every fill-up: Make it a habit to click it several times.
- Keep the battery in good condition: Clean terminals and check voltage regularly.
- Use a fuel system cleaner: Add a quality cleaner to your tank every 3,000–5,000 miles to prevent injector clogging.
When to See a Mechanic
While many engine light issues can be handled at home, some problems require professional help. See a certified Harley technician if:
- The engine light flashes (indicating a severe misfire that can damage the catalytic converter).
- You’re getting complex or multiple codes you can’t interpret.
- The bike is running poorly, overheating, or making unusual noises.
- You’ve tried resetting the light multiple times and it keeps returning.
- You’re not comfortable working on electrical or engine systems.
Remember: A flashing check engine light is a red flag. Stop riding and get it checked immediately.
Final Thoughts
Resetting the engine light on your 2018 Road Glide doesn’t have to be intimidating. With the right tools—especially a good OBD2 scanner—and a methodical approach, you can safely clear the light and get back on the road with confidence.
But remember: Resetting the light is only half the job. The real work is diagnosing and fixing the problem that caused it in the first place. Whether it’s a simple gas cap or a faulty sensor, addressing the root cause ensures your bike runs smoothly and reliably.
By following this guide, you’ll not only learn how to reset the engine light, but also how to maintain your Road Glide like a pro. Stay safe, ride smart, and keep that engine light off for good.